1. Field of the Invention
The present invention relates to door bolting devices and, more particularly, to a door bolt adapted to lock the door, enabling the door to be slightly opened without letting people outside the house pass to the inside of the house.
2. Description of the Related Art
Various door locking devices have been disclosed for use to lock the door, and have appeared on the market. In order to let the door be slightly opened without allowing people outside the house to pass to the inside of the house, a door bolt may be used. A conventional door bolt is known comprised of doorplate and a jamb plate. The doorplate is fixedly fastened to the free end of the door panel, having an elongated sliding slot. The jamb plate is fixedly fastened to the doorjamb, having a chain and a slide bolt at the end of the chain for coupling to the sliding slot of the doorplate. There is known another design of door bolt in which the jamb plate has a hinged retainer bar; the doorplate has a hook. When the door closed, the hinged retainer bar is turned toward the hook of the doorplate, enabling the longitudinal sliding slot of the hinged retainer bar to be coupled to the hook of the doorplate.
The aforesaid prior art door bolts are still not satisfactory in function. If the person inside the house meets with an accident and is unable to open the door, any person outside the house cannot unlock the door bolt from the outside. In this case, a person outside the house must destroy the door to get into the inside of the house.